1. Field of the Invention
This invention relates to cleaning machines and, more particularly, to an upright water extraction cleaning machine.
2. Description of the Related Art
Water extraction cleaning machines have long been used for removing dirt from surfaces such as carpeting, upholstery, drapes, and the like. The known water extraction cleaning machines can be in the form of a canister-type unit as disclosed in U.S. Pat. No. 5,237,720 to Blase et al. or an upright unit as disclosed in U.S. Pat. No. 5,500,977 to McAllise et al. and U.S. Pat. No. 4,559,665 to Fitzwater.
The current water extraction cleaners can be difficult to use and often have limited adaptability for a variety of cleaning conditions. For example, none of the known water extraction cleaners can quickly and efficiently vary the mixture ratio of detergent and water. In addition, none of the known upright water extraction cleaners can automatically adjust the height of the roller-type agitation brush in response to changes on the surface being cleaned. Another problem inherent with the known water extraction cleaners is ease of use in filling and emptying the clean water tank and recovery tank. Finally, none of the known prior art water extraction cleaners can quickly and easily convert between on-the-floor cleaning and off-the-floor cleaning with an accessory hose and cleaning tool.